The present invention relates to a device for the transdermal delivery of medications. More specifically, the present invention relates to a transdermal medication delivery device capable of remote controlled administration of medication.
Individuals with chronic or terminal medical conditions are frequently required to take many different medications on irregular schedules. Often these individuals are hospitalized in order to control the administration of the medications and for monitoring purposes. The hospitalization and discomfort of around-the-clock injections, intravenous medication administration, oral and nasal medication administration, and so forth undesirably lower the quality of life for patients who are suffering from chronic or terminal illnesses. In addition, hospitalization undesirably increases the per patient cost of medical care.
Even, for those ambulatory individuals who are not hospitalized but require long-term medications, the administration of these medications is disadvantageous for the patient. For example, these patients are typically obliged to carry their medications with them at all times, to administer medications at inconvenient times and in awkward locations, or to stay home to follow their medication regime thus decreasing the quality of life for these xe2x80x9cambulatoryxe2x80x9d patients.
Furthermore, the routes taken to administer these medications have several disadvantages. For example, oral administration is often associated with variable absorption, with blood medication levels sometimes rising to toxic levels or falling to subtherapeutic levels. In addition, oral administration can cause side effects, such as gastrointestinal upset. Injections, whether intramuscular, intravenous, or subcutaneous can be painful, cause scarring, or require extensive training of the patient or caregiver to administer the injections.
The disadvantages associated with these medication schedules and medication routes decrease patient compliance, sometimes causing patients to intentionally omit their treatments. When a patient has several medications, the sheer number of medications and the complexity of the medication administration schedule can also cause treatments to be inadvertently missed or doubled. Yet another problem arises with patients who have impaired mental faculties, such as with some older patients and those suffering from Alzheimer""s disease. Patients with impaired mental faculties may simply forget to take their medications.
To overcome some of the problems associated with these medication delivery routes, researchers are increasingly studying the efficacy of administering medications through transdermal delivery, i.e., the absorption of the medications through the skin. Some of the aims of transdermal medication delivery are to maximize the bioavailability of the medication, to optimize the therapeutic value, to minimize side effects, to simplify the administration of the medications, and to generally allow the patient a higher quality of life.
One of the most important advantages of the transdermal medication delivery route is that it provides constant and continuous absorption of the drug, thus keeping blood levels within the xe2x80x9ctherapeutic windowxe2x80x9d. In addition, through transdermal delivery, medications may be introduced into the systemic circulation without initially entering the portal circulation where they may be metabolized into a pharmacologically inactive form (first pass effect). For medications that are normally taken orally, transdermal delivery can eliminate factors such as pH changes and food intake that influence gastrointestinal absorption.
In addition, the transdermal administration of medications may allow rapid termination of drug input should side effects occur. Furthermore, there is less discomfort associated with transdermal medication administration, which increases patient compliance over prior medication administration routes. The transdermal route is, therefore, a suitable route for the administration of very potent drugs, drugs with short half lives and low therapeutic indices, drugs which are subject to significant first pass effects, or drugs that cause uncomfortable side effects or are painfully administered.
A number of transdermal drug delivery systems have been developed and are currently in use. These devices, typically in the form of a drug patch, contain the active constituent dispersed or suspended in a reservoir, with its rate of release controlled through passive administration by matrix diffusion or by its passage through a controlling membrane. A drug patch is desirable for patient use because it is inconspicuous, easy to use, and allows the patient to be ambulatory while taking the medication.
The drugs incorporated into these transdermal drug delivery systems include nitroglycerin, which has been used for the treatment and prevention of angina pectoris, scopolamine for the treatment of motion sickness, and nicotine for relieving the symptoms associated with smoking cessation. In addition, cardiac drugs, such as the antihypertensive, clonidine, and steroid hormones such as estradiol have also been successfully delivered through the skin into the body""s blood circulation.
Prior art transdermal drug delivery systems that employ passive administration techniques using a drug patch allow only medications having small molecular configurations to be administered. Hence, they are of limited use for medications having large molecular configurations. In addition, the prior art transdermal drug delivery systems are capable of delivering only one medication, which may be unsatisfactory for use with patients suffering from chronic or terminal medical conditions who require several medications.
Moreover, prior art transdermal drug delivery systems do not include monitoring capability. Thus, patients suffering from chronic or terminal medical conditions, or having impaired mental states may still require hospitalization to verify that they are receiving their medications, that the medications are being administered in the correct dosages, and that their vital signs, such as blood pressure, heart rate, and so forth, are remaining in an acceptable range.
Accordingly, it is an advantage of the present invention that a transdermal medication delivery device is provided.
It is another advantage of the present invention that a transdermal medication delivery device is provided for remote controlled administration of medication to a patient.
It is another advantage of the present invention that a transdermal medication delivery device is provided that delivers more than one medication for absorption through the skin of the patient.
Another advantage of the present invention is that a transdermal medication delivery device is provided that allows the vital signs of a patient to be monitored from a remote location.
Yet another advantage of the present invention is that a transdermal medication delivery device is provided that is comfortable for the patient, biocompatible, mechanically strong, and simple to use, and allows a patient to remain ambulatory while receiving one or more medications.
The above and other advantages of the present invention are carried out in one form by a transdermal medication delivery device for remote controlled administration of a medication for absorption through the skin of a patient. The device includes a chamber containing the medication and a valve having a valve inlet in fluid communication with the chamber and having a valve outlet. A medication delivery component is in fluid communication with the valve outlet and has a surface adapted to be in contact with the skin of the patient when in use. The device further includes a controller for controlling a flow of the medication through the valve and a wireless communication interface in communication with the controller for receiving a medication control message from a remote location. The medication control message instructs the controller to regulate the valve to adjust the flow of the medication from the chamber to the surface of the medication delivery component.